1. Field of the Invention
The present invention relates to an obstacle detecting apparatus and a device for protecting a vehicle occupant by using the obstacle detecting apparatus, and, more specifically, to the obstacle detecting apparatus and the vehicle occupant protecting device with the use of the obstacle detecting apparatus in which the distance between a vehicle and an obstacle can be detected by using two distance measuring sensors.
2. Description of the Related Art
Conventionally, as examples of an obstacle detecting apparatus and a vehicle occupant protecting device using the same in which the distance between a vehicle and an obstacle can be detected by two distance measuring sensors, collision detecting apparatuses for detecting a collision direction and a collision intensity on the basis of a collision acceleration is disclosed in Japanese Patent Application Laid-Open (JP-A) Nos. 6-56000 and 7-223505, and structures thereof are known.
The structure which is disclosed in Japanese Patent Application Laid-Open (JP-A) No. 7-223505 will be described hereinafter.
As shown in FIG. 21, in an obstacle detecting apparatus and a vehicle occupant protecting device using the same, an obstacle 72 such as another vehicle or the like in the vicinity of a vehicle 70 is detected by obstacle detecting sensors 74, 76 which are installed in the vehicle 70. Accordingly, a vehicle occupant protecting device 80 is operated on the basis of signals output from the obstacle detecting sensors 74, 76. When it is detected that a collision has occurred at the front of the vehicle, the vehicle occupant protecting device 80 is operated on the basis of a signal output from a collision detection sensor 82 and on the basis of signals output from the obstacle detecting sensors 74, 76.
Although the obstacle detecting apparatus and the vehicle occupant protecting device using the same can detect the relative velocity of the vehicle 70 with respect to the obstacle 72, the apparatus and the device cannot detect the collision angle formed between the obstacle 72 and the vehicle 70. Accordingly, it is not possible to predict a collision state including a collision angle and a relative velocity in the direction of the collision angle (i.e., collision velocity) at the time at which the obstacle 72 and the vehicle 70 collide.